Furnace-retort.



D P. NISBET FURNACE RETORT. APPLICATION FILED NOV..17, 1910.

' Patented Sept. 15, 19M.

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n. F. NISBET; FURNACE RETORT.

APPLICATION FILED NOV. 17, 1910- l ,1 1 64% Patented Se t. 15, 1914.

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D. F. NISBET.

FURNACE RETORT.

APPLICATION FILED NOV. 17, 1910 1 1 m gg Patented Sept. 15,1914.

fjw zw D. P. NISBBT. FURNACE-REPORT.

APPLICATION FILED NOV 17. 19101 Pate med Sept. 15,1914.

6 sums- 5111331 5Q z w W Uni DAVID F. NISBET, OF GRAFTON, PENNSYLVANIA.

FURNACE-RETORT.

Specification of Letters Patent.

Patented Sept. f5, 1914..

Application filed November 17, 1910. Serial No. 592,847.

To all whom it may concern Be it known, thatl, DAVID F. NISBET, a citizen of the United States, residing at Grafton, in the county of Allegheny and tate of Pennsylvania, have invented certain new and useful Improvements in Furnace- Retorts; and I do hereby declare the following to be a full, clear, and exact description.

of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in fuel-consuming furnaces, and is applicable to boiler furnaces, metallurgical.furnaces, or any other furnaces using bituminous coal.

My invention is an improvement on the means for burning fuel by a method similar to the one described in previous Letters Patent issued to me, viz., No. 910,305, dated Jan. 19, 1909, and utilizes the same principles of combustion, viz., providing separate air supplies for the combustion of the volatile hydrocarbons and for the combustion of the fixed carbons, but provides a .simpler means for supplying air to the fuel, and may be usedeither alone or in combination with the apparatus described in said previous Letters Patent. My invention consists in improved means for supplying air to the fuel at the point where the fuel is introduced into the furnace, in quantities suflicient for the complete combustion of the volatile hydrocarbons contained in the fuel, and in means for causing the fuel to pile, or mass, at this point, in

such a manner as to compel the complete distillationand combustion of the volatile. hydrocarbons, before the fuel is forced onto a grate, and the remaining portion, consisting chiefly of fixed carbon, is burned in the usual manner by either natural or forced draft. This method permits the separate and inde-. pendent regulation of the air supply for burning the volatile combustibles. and the air supply for burning the fixed carbons, effecting perfect combustion with the least possible amount of air, thereby preventingthe formation of smoke and securing great economy 1n the use of fuel.

Referring to the drawings, which show various modifications of my invention,

1 Figure 1 is a horizontal section of one end of-a locomotive firebox, showing one form ofmy invention. Fig. 2 is a sectional side ele nation on line a. a. of Fig. 1. Fig. 3 is a transverse section on'line b. b. of Fig. 1. Fig. 4 is an elevation of the installation shown in Figs. 1 and 2. Fig. 5 is a horizontal section of the firebox of a reheating furnace, showing a plunger type of fuel feeding mechanism and twyers for supplying air blast. Fig. 6 is a sectional side elevation on the line a. a. of Fig. 5. Fig. 7 is a horizontal section through the twyers on the line a. of Fig. 8. Fig. 8 is a transverse section through the twyers and blast box on the line Z). Z). of Fig. 7. Fig. 9 is a sectional elevation on the line 0. c. of Fig. 8. Fig. 10

is a horizontal section through the firebox of a reheating furnace on the line a. a. of Fig. 11. Fig. llis a sectional side elevation of the firebox on the line 6. Z). of Fig. 10.

Describing the construction and operation of my fuel consuming apparatus: 1 is a hopper, to the lower end of which is affixed an annular casing 2, partly open at the top and communicating with the hopper, and having one end flanged for fastening to the retort 3 and to the mud-ring 4' of the boiler; within the casing, a feeding worm 5 is revolubly mounted on a fixed spindle 6 held firmly in a cover plate 7 bolted to the casing 2. The Worm 5 is driven through a Worm gear on its outer end by the shaft 8 and worm 9, or other suitable means. The retort 3 is fastened to the mud-ring 4 and may be provided at the lower side with the doors 10, and is supported at its inner side by the rest bar 11. The retort 3 is provided with a detachable edge, or lip, 12, which is preferably divided transversely into two or more sections, and is easily and cheaply replaced. The retort 3 is provided with chambers 13 having detach-. able caps or twyers lt, through which air is forced from the blast pipes 15. The grates 16 are mounted in bars. 17 and operated through the rock-shaft 18, levers 19, and links 20 and 21, by any suitable means.

In operating my apparatus, fuel is introduced into the hopper 1 and passes by gravity into the casing 2 and surrounds the revolving-worm 5, which forces the fuel into the retort 3. When the fire in the furnace is in full action, the fuel will'be massed in front of the feeding mechanism, approximately' to the dotted line at. There will be a zone of incandescent fuel approximately from the line y to the line or, through which the hydrocarbon distillates, thoroughly mixed with the air from the twyers, must pass, thereby heating the mixture, to the point of ignition and burning the mixture of air and gas completely.- 1 r Since the complete combustion of the volatile hydrocarbons contained in ordinary bituminous coals requires from to 40% of the total amount of airneededfor the complete oxidation of the combustible elements of such coals, it is obvious that means for distilling the hydrocarbons and supplying-the distillates with the necessary air in independent and regulatable quantities is essential 'to. theircomplete combustion to CO F'QThe remaining portion of the fuel,

consisting chiefly.of 'coke, or fixed carbon, being continually forced upward by the fresh coal being fed intovthe bottom of the retort, passes over the edge of the retort onto the grates 16, where it is progressively fed to the other end. of the firebox, being burned onthe grates in the usual manner. I he type of. grates shown in the drawings is the preferable one, and forms the subject matter of a previous application for Letters "Patent, but it is obvious that any other form of inclined orvfeeding grate maybe used in connection with my invention. p

In another type of installation, 22 is a hopper, affixed to and communicating with the casing 23, which is fastened to the front plate 24 ofthe fur'nace,and to which is fastened, at its outer end, the guide 25 forpthe plunger or pusher- 26. 'In the fur- ;na'ce wall, and running transversely across the furnace, is the blast box 27 ,comm'unicat- .ing through openings in its upper side with the twyers 28, and having a shelf formed by anextension of its upper side and in substantial alinement therewith, extending into'the furnace. To the end of this shelf is fastened an upwardly inclined plate, or shelf, 29, the-wholeforming a retort where the fuel will be massed before passing over the edge oft-he retort onto the grates 30.

. plete combustion.

Air under pressure is introduced into the blast box 27, whence it passes into the twyers, and through the openings in the inner end' of the twyers into the mass of fuel in the retort, mixingwith the volatile matter which is being distilled from the fuel in the retort and nisuring its com- In' this type of installation, the fuel is placed in the hoppers 22 and falls 5 gravity in front of the reciprocating p ungers 26, which force it into the furnace through the openings between the twyers 28." The "continued operation .of the plungers cause the fuel to pile in the retort around and above the twyers, the distillation and combustion of the distilled gasses and the burn' mg of the fixed carbons taking place as hereinbefore described.

' Figs. 10 and 11' illustrate another con-.

struction embodying the "same principles.

misses The blast box 31'is placed over theopenings' in the furnace wall through which the fuel is fed, and; forms,a supporting beam for the superimposed walL it is provided at its lower side with openings into the twyer boxes 32, which have replacable caps or twyers 33.- The mechanism for feeding the fuel through the openings into the furnace is similar to that shown'in Figs, 1 and 2, and

the distillation, mixing with air, and combustion of the volatile hydrocarbons' and subsequent combustion ofifixed carhons occurs" as'hereinbefore described. f "f The object of making the fuel feeding app'aratu's'in separate units is. twofold,-

first, to provide convenient means for'feed- 'in'g'the' fuel into the furnace between the twyers,'1and second, to make the apparatus convenient'of application to" any width of firebox, by'using a suitable numberv of units.

Although the installations illustrated in the drawings are shown as being fitted to the front wall of the furnace, it is obvious that any of them might be fitted to the side walls and feed the fuel toward the longitudinal axis of the furnace, withoutdeparting from my invention.

The advantages of my invention are many. It'is simple and cheap to constructand efficient and reliable in operation. The twyers being of sufficient size to convey the total "amount of'air necessary for the complete combustion of the volatile matter contained in the fuel, and the air being supplied at. the point where the volatile matter is distilled, the combustion of the volatile matter is quick and complete, giving a hot flame without soot or smoke.

-Whe'n desired, extremely high rates of combustion may be maintained. forlong periods without decreasin the efliciency or economy, and fires may e banked without danger of the fire Working back into the hoppers. a

Havingdescribed my invention, I claim:

1. In fcombination with a furnace, .a re tort extendingieontinuously along j the inner side of the front wall of the furnace, comprising a shelf terminatinginwardly in an upwardly inclined extension "designed to mass the fuel over and around the twyers, means for feeding fuel into the retort, at different localities throu h; a "pluralityor openings in the front we l of the furnace,

2. In combination with a furnace, a re-- tort extending "continuously along the inner 'sidepf the furnace wall and having a shelf terminating inwardly in an upwardly inclined extension for the purpose of causing length of the retort having their openings below the level of the upper edge of the shelf, means for admitting air; to the twyers, and means between the spaced twyers for feeding fuel into the retort.

3. In combination with a furnace, a retort extending continuously along the inner side of the furnace wall and having a shelf upwardly inclined in the direction of the movement of the fuel so as to cause the fuel to mass over and around twyers, a

plurality of twyers spaced along the length of the retort having their openings below the level of theupper edge of the shelf, means for feeding fuel to the retort through openings between the said twyers, and means for supplying air to the twyers.

In testimony whereof, I have signed my nameto this specification in the presence of two subscribing Witnesses.

' DAVID F. NISBET. 

